by: Chel Terrell
Managing Editor, The Beefmaster Cowman
Embryo transfer (ET) can be an incredible asset to your operation, whether you're a “seasoned” breeder or relatively new to the cattle business. The technology has proven beneficial for upgrading quality in a shorter amount of time – allowing a producer to achieve the desired forward progress in their herd by adding elite genetics without having to invest resources in multiple high-dollar animals.
A successful ET program isn't a speedy endeavor, though. Thoughtful planning must take place for the desired outcome to be achieved. And given the cost of the technology, taking the proper steps from the beginning will enable producers to maximize success long term.
“Using embryo transfer and artificial insemination are great ways to increase your genetics rapidly,” said Casey Ballard, Legacy Genetic Resources, Bryan, Texas. But to achieve this goal, Ballard emphasizes that producers must first have several things in place – a good record keeping system, sound nutrition program, a focus on donor and recipient cattle selection, health and fertility, and a proper plan. The amount of time a breeder puts into preparing for a successful embryo transfer day by paying attention to these details will directly reflect in the results.
Rely on Records
“First of all, record keeping is a big asset to your program,” Ballard said. “You need to know the history of the cow and you need to keep accurate records. I hear all the time, ‘Well, I think she calved about three months ago,' or ‘I know she hasn't been with a bull,' only to find out that she's actually pregnant when we palpate her.”
Producers need to be able to track how often a female has been synchronized and transferred to. Knowing the number of calves she's had either naturally or born via embryo transfer is especially important for the ET technician.
“There are a number of software programs available to help producers track this information,” Ballard said. “But even a simple pocketbook with everything written down is better than having nothing.”
Manage Donors and Recipients to Maximize Results
Proper donor and recipient selection and management rank high on the list with good record keeping for successful production and transfer of viable embryos in a program. The American Embryo Transfer Association (AETA) says the national average of viable embryos per flush is 6.9 and that total viable recovered ova is only 54.6 percent. Therefore, this part of a solid management plan is invaluable.
Brad Stroud, DVM, Stroud Veterinary Embryo Services in Weatherford, Texas, has spent the last 30-plus years helping clients with embryo transfer and says that donor selection and management must be a priority.
“One of the first things a producer needs to do is determine which animals in the herd are going to be donor cow candidates. Genetically, some animals are more superior and certain matings are more valuable than others,” he said. “Beyond that, we look at reproductive health of the donor going into the embryo transfer program. Are these cows pregnant, lactating and raising a calf at side or are they dry, overweight cows?”
Fat tends to yield less results in an embryo transfer program as opposed to moderately-fleshed animals, he said. “The dry, overweight cows can sometimes be problematic in an embryo transfer program as far as producing numbers of embryos.”
Before purchasing donors outside the herd, breeders need to know the animal's history. “Just because you've got a really high-dollar, valuable female doesn't mean she's going to produce embryos,” Stroud said. “It's really important that a person does their history before purchasing a donor outside the herd.” He especially warns against buying “worn out” donors.
“We need to look at genetic value first, then physical reproductive traits second,” he said. “You have to be careful because sometimes these older donors have made a reputation of producing lots of calves, but at some point they run out of gas themselves. One could easily get caught up in the genetic value of a female and not know the reproductive status of that animal.”
Stroud prefers to flush cows with calves at side, as does Ballard. “That tells you a lot about her fertility status; she's had a calf and is lactating,” Stroud said.
“We like to see pairs, especially for first time embryo transfer. The best success we've seen is with females that have a calf at side that are 60 to 70 days post partum. These are good, fertile cattle,” Ballard said.
Managing recipients to optimize conception rates is the next priority, Stroud said.
“There are all kinds of ways to manage and synchronize recipients,” he said. “Selecting recipients to go into the herd is almost like selecting a donor cow. You'd prefer to have a cow with a calf at side and that's lactating because then we know she's fertile. Cows that are in the two- to five-year-old range in age are ideal to get the best conception rates in an embryo transfer program.”
Proper nutrition is a critical part of this equation. Cows need to be in good body condition in order to raise a healthy calf, breed back and maintain a pregnancy, Ballard said. “Your recipients are just as important as your donor cattle. They need to be on a good plane of nutrition 30 to 60 days prior to transfer, then continue on that plane for 30 to 60 days after transfer. This will help pregnancy rates.”
“Recipients need to be in good body condition and in moderate flesh, not thin and not too fat, so monitor their forage intake,” Stroud said. “Underfed cows in poor body condition may not cycle at all, which can be very frustrating on transfer day to go in and palpate these cows that are not ready to receive an embryo.”
Overfed cows can also be a major issue when it comes to an unsuccessful embryo transfer process. “Obesity is the single reproductive problem that I've seen the most in my career over the years,” Stroud said. “When you get obesity in cattle, fertility and reproduction go south.”
Stroud also warns producers to be careful about selecting open cows from the herd to use as recipients. “Cows that aren't cycling and didn't have a calf might not have for a number of reasons,” he said. Using accurate heat detection and ultrasound technology are important, which can indicate if a corpus luteum (CL) is present.
“It does take time to heat detect,” he said. “If you do heat detect and synchronize those recipients with good observed heats, that will yield you your best conception rates after transfer whether it's fresh or frozen embryos.”
Keep in mind the importance of optimal health for donors and recipients, in addition to sound nutrition, for an effective transfer day.
“Work with your veterinarian to develop a proper vaccination and deworming program for your specific herd and breeding program,” Ballard said. “A healthy herd will impact the success of your reproductive plan.”
Facilities, Skill are Necessary Needs
Practitioner skill and proper facilities are critical “non-animal factors” for a successful embryo transfer program, Stroud emphasizes.
“The single most important factor that a cow owner can count on is a donor manager or artificial insemination technician that is capable of heat detecting and inseminating these donors to make the embryos,” he said.
“The second most important factor is an experienced embryo transfer technician. The more experience an ET technician has with the whole process, the better they can reliably and accurately minimize negative flushes. They can come onto a farm, look at the resources that are there or are needed, and make those adjustments so that the infrastructure of that program is intact.
“If the owner is willing to invest some money and get quality people with experience involved, it can pay off.”
Good working facilities reduce stress on both practitioners and animals and aid in a positive working day.
“I can tell you that over the years, the infrastructure (alleyways, loading areas, chutes, etc.) must be adequate for optimal cattle flow and to reduce stress on the cattle,” Stroud said.
“The more stress you put on these cattle, you could see lower conception rates, so you need to have good facilities,” Ballard said. “They don't have to be state-of-the-art, but they need to be user friendly to the workers and as stress free on the cattle as possible.”
Keys Ingredients Come Together
When producers follow a well-developed management plan, they can reap rewards with embryo transfer technology. With the multitude of factors that must come together for success – record keeping, selection, nutrition and health of donors and recipients, good working facilities and skilled, knowledgeable technicians – it's ok to ask questions, especially if you're new to the process.
“Call your veterinarian or embryologist; don't be afraid to ask questions,” Ballard said. “There are so many small little things that we know; if we can discuss it with you, we can try and find the solution and get you to where you need to be for breeding success.”
(Reprinted with permission from the March 2015 Beefmaster Cowman.)
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